The SD1 Manual say in "THE SAMPLER" category:

"One of the special
features is the possibility to create a Multi-sample file exploiting up to a maximum of 64 samples arranged over the keyboard and therefore
achieving an amazing timbre over the octaves of the keyboard."

and it say also:

"Up to eight Multi-sample files can be achieved with 32 samples each at the most."

Can you explain this difference to me?

I experimented we can add 62 samples in one msp, but the drum kit read only 32 first waves. I have 3 msp files :ORIENT01.MSP ORIENT02.MSP and ORIENT03.MSP. Each one play in a zone of the keyboard, and when I load this 3 files (block), the keyboard play fully in all zones! I think THE SD1 play this MSP files together! This is a very cool feature ! undocumented?

Then, I can play ... 32 * 8 = 256 samples together.... !!!!!

I dream?